Conventionally, semiconductor devices have been known that include a semiconductor switch including what is called a MOS (Metal-Oxide-Semiconductor) structure. Such a semiconductor device may include a Zener diode for overvoltage protection in some cases. The Zener diode is configured to include an n-type semiconductor layer and a p-type semiconductor layer arranged adjacent to each other.
For example, in a case where the semiconductor switch is an insulated gate bipolar transistor (Insulated Gate Bipolar Transistor: IGBT), a first Zener diode is provided between a collector electrode and a gate electrode, and a second Zener diode is provided between the gate electrode and an emitter electrode. The first Zener diode and the second Zener diode are connected in series to each other.